Large temperature variability in the southern African tropics since the Last Glacial Maximum

Abstract

The role of the tropics in global climate change is actively debated, particularly in regard to the timing and magnitude of thermal and hydrological response. Continuous, high-resolution temperature records through the Last Glacial Maximum (LGM) from tropical oceans have provided much insight but surface temperature reconstructions do not exist from tropical continental environments. Here we used the TEX86 paleotemperature proxy to reconstruct mean annual lake surface temperatures through the Last Glacial Maximum (LGM) in Lake Malawi, East Africa (9°-14°S). We find a ∼3.5°C overall warming since the LGM, with temperature reversals of ∼2°C during the Younger Dryas (12.5 ka BP) and at 8.2 ka BP. Maximum Holocene temperatures of ∼29°C were found at 5 ka BP, a period preceding severe drought in Africa. These results suggest a substantial thermal response of southeastern tropical Africa to deglaciation and to varying conditions during the Holocene. Copyright 2005 by the American Geophysical Union.